Previous work has shown that organic anion transport occurs in both the ciliary body and the iris by parallel but independent processes. We have shown non-specific effects of autonomic drugs and corticosteroids on this transport and propose to study these drugs' effects on other transport systems in the anterior uvea. Using fluorescein as a marker dye we further propose to study the anatomical localization and directionality of transport of these transport systems using quantitative histochemical techniques currently under development in this laboratory.